The use of combing wheel feed means to feed cut sheets to a printer is well known; for example, see U.S. Pat. No. 640,368.
While the broad suggestion of a resilient, or resiliently mounted, combing wheel is contained in UK Pat. Nos. 1,244,405, where it is suggested to provide resilient mounting for the roller's spindles to extend the path of engagement of each roller with the stack, and 1,427,357, where it is suggested to provide cushioning against any jar, rattle or shutter resulting from the intermittent engagement of the combing wheel with paper to be fed to a copier's transfer station, these suggestions fall short of the teaching of the present invention.
The present invention, in its broader aspects, deals with the construction and arrangement of a combing wheel whose axis of rotation is parallel to the plane of sheets to be fed, wherein the wheel's individual sheetengaging-rollers are mounted in a rubber hub whose spring rate and damping coefficient are selected to insure that each individual roller engages the sheet with substantially continuous contact, during its period of intermittent contact, as controlled by the spring rate, and with a force profile having reduced force excursions, between maximum force and minimum force, as determined by the damping coefficient.
More specifically, the combing wheel of the present invention comprises a metallic inner hub mounting the wheel to a drive shaft. This hub is encircled by a rubber hub having a pair of axially spaced rubber flanges, the space therebetween defining an annular cavity for the sheet engaging rollers. Each flange includes radially extending mounting slots, pairs of which define a radial plane which intersects the wheel's axis of rotation. Each roller, for example ten in number spaced 36.degree. about the wheel's circumference, is freely supported for substantially frictionless rotation on a metal shaft whose length corresponds to the axial spacing of the rubber hub's spaced flanges. The rollers are mounted to the rubber hub by friction-fit of their respective metal shaft's into the mounting slots formed in these flanges. Thus, the rollers' axis of rotation are parallel to the wheel's axis of rotation. The combing wheel assembly is completed by a pair of metal caps, of smaller diameter than the diameter defined by the outboard surface of the rollers, but of larger diameter than the circle defined by the roller's rotational shafts. These two caps mount to opposite sides of the innermost metal hub, without physically engaging the roller's rotational shafts. Each cap includes an inturned annular flange which overhangs the ends of the rollers' rotational shafts, thus imprisoning the shafts within the combing wheel.
Generically, the term combing wheel, as used herein, is intended to encompass not only the vertical orientation shown (i.e. the plane of combing wheel rotation is perpendicular to the flat surface of the sheets being fed), but is also intended to encompass a horizontal orientation, or a tilted orientation (i.e. the plane of rotation being between vertical and horizontal). Also, while a circular wheel is preferred, its equivalent may be to support rollers or the like on a flexible belt or chain which does not travel a closed circular course. In addition, while the combing wheel surface, which engages the surface of the sheets being fed, is shown in its preferred form as a hard, friction-free roller, it is within the scope of the present invention to utilize a resilient roller, or a roller having friction, or a non-rotating sheet engaging surface, or combinations thereof.